Proteolysis targeting compound with tissue targeting capability and use thereof

This application is the U.S. National Stage of PCT/CN2021/090962 filed on Apr. 29, 2021, which claims priority to Chinese Patent Application 202010354369.8 filed on Apr. 29, 2020, the entire content of both are incorporated herein by reference in their entirety.

The present invention relates to the field of medicinal products and in particular to a compound or a pharmaceutically acceptable salt, stereoisomer, solvate or polymorph thereof. The compound is a proteolysis targeting chimera (PROTAC) having with the specific tissue targeting ability. The structure of the compound comprises three parts, i.e., A-BD-CON, wherein the part A is a PROTAC, one end of the structure thereof is a target protein ‘binding ligand, and the other end is a ubiquitin ligase ligand; and the part CON is a ligand of an asialoglycoprotein receptor (ASGPR), having a function of enabling the specific tissue targeting function of the PROTAC. The invented compound further achieves the functions of enriching in liver tissues and is able to targeting cells in the tissue. The invention achieves improved druggability on the basis of the PROTAC having a high medicine making difficulty, and with improves the higher solubility of the PROTAC, and cellular membrane permeability, therefore produces enhanced and the pharmaceutical effect on a the specific target tissue, thus generally improving the medicine making properties.

Cancer is a disease with high morbidity and mortality worldwide, posing a serious threat to human health and has become one of the important social problems faced by countries around the world. Liver cancer is the fourth most common tumor in China, with an annual increase of about 460,000 cases and the second highest mortality tumor in China (mortality rate of 26/100,000). In the world, there are more than 840,000 new liver cancer cases every year, and China accounts for about 50% of the world's new liver cancer cases every year. Lacking effective treatment for liver cancer, the five-year survival rate of the disease is only 10%. Effective ways of prevention and control of liver cancer are in great need.

Hepatitis is another major liver disease, and with hepatitis B as the major subtype in China and other east Asian countries. At present, there are about 90 million hepatitis B virus carriers in China. According to the World Health Organization, only 8% of hepatitis B patients in the world have been under antiviral therapy, and about 10% in China. Ubiquitin-mediated proteolysis is among the most important down regulations of proteins in cells. Ubiquitin-mediated proteolysis pathway can degrade 80%˜90% of ubiquitinated proteins in cells, and is involved in regulating cell cycle, proliferation, apoptosis, metastasis, gene expression and signal transduction, almost all life activities. This process occurs under the synergistic action of ubiquitin activating enzyme E1, ubiquitin conjugating enzyme E2 and ubiquitin ligase E3. After ubiquitination, the substrate protein is degraded in the proteasome. Since ubiquitin ligase E3 has specific recognition ability to the substrate protein, ubiquitin mediated proteolysis is specific. PROTACs are essentially heterobifunctional small molecule compounds structurally comprised of three parts, i.e. an ubiquitin ligase E3 ligand and a target protein binding ligand linked by a linker. PROTACs pull the target protein closer to the E3 in the cell, forming target protein-PROTACs-E3 enzyme. The target protein is tagged with ubiquitinated protein through the E3 ubiquitin ligase, which starts the powerful ubiquitinated hydrolysis process in the cell, and specifically degrades the target protein via the ubiquitin proteasome pathway to achieve the goal of treating diseases.

CN108601764A disclosed a series of VHL ligand structures for use in PROTAC as E3 ubiquitin ligase ligands.

Being different from “occupancy driven” mode of the traditional drug (that is, it needs to occupy the active site of the target protein continuously to block its function), PROTAC only needs to provide binding activity to trigger binding of the target protein to E3 ligase and thus cause degradation when it contacts with the target protein, which is called “event driven”. Long time and high intensity binding to the target protein is not required. Therefore, PROTAC can target traditionally undruggable targets, such as proteins with smooth surface that lack small molecule binding regions. Many targets that cannot be targeted with small molecules or antibodies can be targeted with PROTAC technology. PROTAC molecules can induce ubiquitination and degradation of target proteins only by binding to the surface of target proteins for a short time. This process is not limited by the traditional balanced occupancy, and is more similar to a catalytic behavior, which can be reused.

PROTAC has the following advantages in theory: the dosage is small, a catalytic level is enough, and the safety dose range is wide; drug resistance caused by target protein mutation/overexpression is overcome; and it is affinity independent and has high selectivity; and can clearance of protein accumulation.

Despite of the advantages mentioned above, PROTACs have the limitation in druggability. PROTAC molecular weight is generally above 700, breaking the drug-like rules in traditional small molecule pharmaceutical chemistry. They violate small molecule drug-like rules either in terms of molecular weight or complexity, so there inevitably exist many challenges in druggability, such as water solubility, permeability, PK/PD, etc. Off-target toxicity is also of common concern. PROTAC involves in an event driven catalytic reaction. Whether it affects on the expression of target proteins in normal tissues is unclear.

The asialoglycoprotein receptor (ASGPR) is an endocytosis receptor specifically expressed in hepatocytes, and can specifically recognize and bind non-reducing D-galactose (β-D-galactose, Gal) or N-acetylgalactosamine (GalNAc) that are terminal glycosyls of N-linked asialoglycoprotein, especially trimeric and quadruplex glycoproteins. In recent years, breakthroughs have been made in the liver targeted delivery of nucleic acid drugs using GalNAc, a high affinity ligand of ASGPR, as a targeting molecule. For example, by connecting the conjugated part containing terminal galactose or its derivatives to nucleic acid, the nucleic acid molecule can bind ASGPR and thus target liver cells. For example, see WO2009/073809, WO2011/104169 and WO2012/083046. However, applications and researches on other aspects of ASGPR ligands have not been reported yet.

In order to overcome the above-mentioned defects of PROTAC compounds in the prior art, the present invention provides inventively a combination of the ligand of the asialoglycoprotein receptor (ASGPR) with PROTAC compounds. The inventors find that using a specially designed linker surprisingly improves the solubility of the compound, the cellular permeability and biological effect on the liver tissue, and achieves the compound enriching effect in liver tissue and targeting to cells. The compounds can be decomposed into PROTAC and ASGPR ligands through cell endocytosis and lysosomal functions. The ASGPR receptor is recycled back to the cell surface. PROTAC can degrade the target protein. The present invention achieves the improvement of the transmembrane transport of PROTAC, lead to better efficacy in liver tissue, and generally improved druggability.

The present invention provides a compound or a pharmaceutically acceptable salt, stereoisomer, solvate or polymorph thereof. The compound is a proteolysis targeting chimera having improved solubility, tissue targeting ability and better druggability.

The structure of the compound comprises three parts: A-BD-CON, wherein the part A is a proteolysis targeting chimera (PROTAC), one end of which is a target protein binding ligand and the other end is a ubiquitin ligase ligand; and the part CON is a ligand of an asialoglycoprotein receptor (ASGPR), which has the comprehensive function of improving solubility, enabling targeting of PROTAC to specific tissues and cells and improving the medicinal product properties.

The present invention is realized through the following aspects:

In a first aspect, the present invention provides a compound of following formula or a pharmaceutically acceptable salt, stereoisomer, solvate or polymorph thereof, the compound consisting of following three parts:

and LN is a linker of Q and CON and is selected from a carbon chain of 3-20 carbon atoms, and any CHin the carbon chain is optionally substituted by O, NH, or C(O).

In a second aspect, LGE in the compound described in the first aspect is a ligand of ubiquitinated E3 enzyme, preferably a ligand of Von Hippel-Lindau tumor suppressor (pVHL), and more preferably a structure of following formula,

In a third aspect, the compound described in the first and second aspects is represented by the following formula:

In a fourth aspect, CON in the compounds described in the first to third aspects has a structure of following formula:

In a fifth aspect, CON in the compound described in the first to fourth aspects is selected from the following structures:

In a sixth aspect, LGP in the compound described in the first to third aspects is selected from the following structural units:

In a seventh aspect, LGP in the compounds of any one of the above aspects is a ligand of cancer associated targets, microbial associated targets, immune diseases associated targets, neurodegenerative diseases associated targets or metabolic diseases associated targets.

In an eighth aspect, a binding target of LGP in the compounds of any one of the above aspects is selected from the group consisting of kinases, transcription factors, epigenetic reading frames, microtubule-associated proteins, microbial-associated proteins, and so on.

In a ninth aspect, a binding target of LGP in the compounds of any one of the above aspects is selected from the group consisting of EGFR, VEGFR, FGFR, PDGFR, Raf, Braf, RET, FLT, c-Kit, MET, ACVR, ALK, AKT, AhR, AURKA, AR, RAR, ER, BCL, BCR-ABL, BET, BMPR, BLK, BTK, BRD, CDK, CK, CHEK1, CTNNB1, DDR, DHODH, RAS, EED, ESR1, CRABP, CRBN, HER2, HER3, HMGCR, Htt, GNA11, GNA1, GNAS, NQO, TROP, eIF4E, ERK, ERG, ETV, ERRα, EZH2, FAK, IDH1/2, IGF1R, IRAK4, JAK, MEK, MELK, LTK, FKBP, MDM2, HDAC, MER, MCL, MTOR, PAR, PBRM, PCAF, PDE, PD-1, PD-L1, PTK, PARP, PDXK, PLK, PKB, MAPK, PI3K, Pirin, RIPK, Rpn13, PRC, P38, TGFβ, AFP, NTRK, NHE, CEA, SOAT1, SNCA, SYK, RNF43, DLK1, gp96, SGK, SMAD, SMO, SFB, SHP, SIK, SRC, STAT3, TBK, TYK3, TRIM, NS3, IRAK4, PCAF, GCN5, Sirt2, Tau, TUB, Wee1, ZAK or their combined targets.

In a tenth aspect, LGP in the compounds of any one of the above aspects is selected from the group consisting of Hsp90 inhibitors, kinase inhibitors, phosphatase inhibitors, MDM2 inhibitors, compounds targeting proteins containing human BET bromodomain, HDAC inhibitors, human lysine methyltransferase inhibitors, compounds targeting RAF receptors, compounds targeting FKBP, angiogenesis inhibitors, immunosuppressive compounds, compounds targeting aryl hydrocarbon receptors, compounds targeting androgen receptors, compounds targeting estrogen receptors, compounds targeting thyroid hormone receptors, compounds targeting HIV protease, compounds targeting HIV integrase, compounds targeting HCV protease, and compounds targeting acyl protein thioesterase 1 and/or 2.

In an eleventh aspect, LGP in the compounds of any one of the above aspects is selected from the group consisting of: sorafenib, lenvatinib, regorafenib, cabozantinib, apatinib, refametinib, carboplatin, cisplatin, oxaliplatin, everolimus, pemetrexed disodium, erlotinib, dasatinib, imatinib, sunitinib, osimertinib, ibrutinib, alecinix, crizotinib, entrectinib, afatinib, axtintib, ceritinib, larotrectinib, brigatinib, neratinib, trametinib, lapatinib, neratinib, fluorouracil, 5-FU, etoposide, gemcitabine, decitabine, capecitabine, doxorubicin, epirubicin, vincristine, temozolomide, vincristine, ifosfamide, mitoxantrone, gefitinib, bortezomib, paclitaxel, docetaxel, pegylated interferon α-2a, interferon α-2a, pegylated interferon α-2b, interferon α-2b, azacitidine, cytarabine, cyclocytidine, irinotecan, topotecan, vidarabine, idoxuridine (IDU), trifluridine, bromovinyldeoxyuridine, magnesium glycyrrhizinate, glycyrrhizic acid, glutathione, polyene phosphatidyl choline, ademetionine, ursodeoxycholic acid, and ulinastatin.

In a twelfth aspect, the compound is selected from the following structures:

Preferably, the compound is selected from WG-1, WG-2, WG-3, WG-4, WG-5, and WG-6.

In a thirteenth aspect, the present invention provides a pharmaceutical composition of any one of the aforementioned compounds.

In a fourteenth aspect, the present invention provides use of any one of the above compounds and pharmaceutical compositions thereof in the manufacture of a medicament for treating tumors, preferably for treating liver cancer.

In a fifteenth aspect, the present invention provides use of any one of the above compounds and pharmaceutical compositions thereof in the manufacture of a medicament for treating liver diseases, preferably for treating hepatitis.

Unless otherwise defined, all terms (including technical terms and scientific terms) used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

The present application will be further illustrated with reference to drawings and following embodiments. However, these embodiments are only for more clearly illustrating, rather than limiting the present invention in any form. The present invention could be implemented in a variety of different ways disclosed herein.

The present invention describes the materials and experimental methods used in the experiment in a general and specific way. Although many materials and operation methods used for the purpose of the present invention are well known in the art, the present invention is still described herein as much detail as possible. In the following, unless otherwise specified, the materials and experimental methods used are well known in the art.

WG series compounds can be synthesized through the following process or by similar route. Among all compounds, WGint4 is the compound A in the general formula of the present invention, which needs to be synthesized individually. WGint8 is the compound CON in the general formula of the present invention, which can be synthesized by referring to the existing technology or purchased from the supplier. Other procedures are share similar routes.

WG-1 (00300639) is exemplified by the following synthesis route:

In comparison with compound WG-1 (00300639), the corresponding WGint4 is WGint4 (003006). The synthesis route of WGint4 (003006) is as follows:

In comparison with compounds WG-4 (00500639) and WG-5 (00600639), the corresponding WGint4 are WGint4 (005000) and WGint4 (006000). The synthetic method is as follows: